QNu Labs, BISAG-N and IIT Gandhinagar sent quantum-secured encryption keys through open air over 5.56 km, a step towards satellite-based quantum communication in India.

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• The trial linked BISAG-N, an autonomous society under MeitY, with IIT Gandhinagar across a 5.56 km free-space optical path.
• QNu Labs, a startup established in 2016, supplied the quantum key distribution device, called Armos, used in the demonstration.
• The link was tested on the night of 27–28 September 2026, and the government publicised the results in early October.
• Quantum bit error rate stayed below 5 percent, which indicates the channel showed no significant sign of eavesdropping.
• The secure key rate was 230 to 260 bits per second, enough for exchanging keys rather than carrying bulk data.
• A pointing, acquisition and tracking system kept the narrow optical beam aligned between the sender and receiver nodes.
• BISAG-N added Vedic Kavach, a post-quantum cryptography layer with quantum random number generation, as a software fallback if the optical channel drops.
• Quantum key distribution uses single photons, and any attempt to intercept them disturbs their quantum state and shows up as errors.
• Free-space links are the building block for satellite-based quantum communication, a stated goal of the National Quantum Mission approved in 2023.
• Quantum-safe keys address the "harvest now, decrypt later" risk to long-lived secrets in defence, banking and power grids.
• The trial ran at night, since fog, dust and sunlight can disrupt free-space optical links, and the "first" claim is the participants' own.